The property possessed by some materials of bleaching articles is known and widely used to remove discoloration or stains from articles. The behavior and mechanisms by which such bleaching agents perform their functions are only partially understood. It is known that many colored materials contain a conjugated chain, that is, a series of double bonds which alternate with single bonds. If one of the double bonds is broken the color is usually destroyed, therefore, an agent which will remove a double-bond linkage may be an effective bleach. A bleaching agent may also act on the groups at the ends of the chain. Bleaching materials are generally categorized as chlorine; hypochlorites and chloramines; hydrogen peroxide and other peroxy compounds; chlorite and chlorine dioxide; and reducing agents.
The need for bleaching agents is growing in view of energy conservation and environmental protection measures. For example, in the detergent industry improved cleansing of fabrics is being sought since washing performance has suffered because of lower wash temperatures, reduced use of phosphate builders and increased use of synthetic fabrics. The use of new bleaching agents is an effective way to restore this lost performance.
A number of peroxy compounds have been evaluated as bleaching agents and some of these have been diperoxoic acids. For example, U.S. Pat. Nos. 3,959,163 and 4,094,808 disclose bleach compositions where the active agent is diperisophthalic acid; U.S. Pat. No. 4,134,850 discloses bleaching compositions where the active agent is a cycloaliphaticdiperoxoic acid; and U.S. Pat. Nos. 2,813,896 and 4,126,573 disclose bleaching compositions where the active agent is an alpha omega long chain aliphatic diperoxoic acid.
Although satisfactory results are achieved using the diperoxoic acids set forth above, there remains a need for new and structurally different diperoxoic acids to satisfy specialized applications in home laundry bleaching. Hence, those skilled in the art of bleach formulation are constantly looking for peroxy compounds for use as bleaching agents in such formulations, and the present invention provides to the art a class of diperoxoic acids that are structurally different from the prior art suitable for use in such applications.